Repalcing Leaking Hoses, HT740 to Exchanger

Glennman · May 25, 2020, 09:19:20 PM

Hello all,

I just finished removing the (2) 1" hoses that lead from the transmission to the heat exchanger on the side of the engine. One had a leak in it (it got scraped or something). In the process, I'm looking at the 1" hose leading from the alternator (or generator) to the side of the oil pan. The 1" hose is in pretty good shape and is attached with hose clamps. Does that hose have pressure behind it? It doesn't seem like it would, since it just dumps into the side of the oil pan.

The point is that it would be very difficult to replace, but while I have the tranny hoses off, now would be the time to do it. It would involve draining all my new oil and putting it back. I'm thinking of leaving the hose there for now. Thoughts? Thanks, Glennman

buswarrior · May 26, 2020, 04:28:32 AM

The alternator hose is just a simple drain, no pressure.

I like to know the age of all the consumables and rubber bits, but that needs to be tempered with timing...

If it looks good, hose clamps are pristine, remember that's hot engine oil dribbling down through there...that one might wait until there is better reason to replace it...? inconvenient to change the oil and put it back vs OCD?

Happy coaching!
Buswarrior

luvrbus · May 26, 2020, 06:34:49 AM

Look close I think the hose you are looking at is the turbo drain hose,if the alternator is mounted on the rear of the engine it drains back through the engine,1 inch is a big hose for a alternator drain ? is that a side mounted turbo on your MCI,most MCI 8 have a side mounted or rear mounted turbo

Glennman · May 26, 2020, 09:07:03 PM

Luvrbus,

I agree that it seems like a rather large drain hose to be coming from the alternator. It is a 1" hose, clamped to a barbed fitting on the side of he alternator at one end, the other onto another barbed fitting into the side of the oil pan. The transmission lines are more like hydraulic hoses with special fittings. The alternator is belt driven (4 belts), and is mounted above and to the drivers side of the transmission. The entire hose is visible, but besides having to drain the oil, the ends are difficult to get to. Since it is only a drain and is not under pressure, I think I will wait on that one.

The turbo is mounted on the top almost exactly in the center of the motor (slightly to the driver's side), and to the front of the engine (above the fuel pump area).

buswarrior · May 27, 2020, 05:00:19 AM

Interesting, swapping an oil cooled into an air cooled position.

One would love to hear the explanation... something thoughtful and technical, or some hourly rated employee who got told fix it with what you can find in the store room...?

You never know what you'll find in a bus...

Happy coaching!
Buswarrior

luvrbus · May 27, 2020, 07:40:46 AM

Quote from: buswarrior on May 27, 2020, 05:00:19 AM
Interesting, swapping an oil cooled into an air cooled position.

One would love to hear the explanation... something thoughtful and technical, or some hourly rated employee who got told fix it with what you can find in the store room...?

You never know what you'll find in a bus...

Happy coaching!

They did some modifications to get a top mounted turbo engine in a MCI 8 also
Buswarrior

Glennman · May 31, 2020, 09:47:44 AM

Hey Buswarrior,

If people don't mind me hijacking my own thread a bit, I wasn't planning to change from oil cooled to air cooled (transmission), although that does sound intriguing. I hear that this takes a lot of heat away from the engine. Have you ever seen that done with an MCI, and if so, where would one install the radiator and fans, etc?

Scott & Heather · June 01, 2020, 03:48:03 AM

Glen I think Bus Warrior was talking about your alternator goin from air cooled to oil cooled which explains the aftermarket oil line.

As for cooling the trans: I just replaced my engine in my coach and whilst at it, I yanked that coolant/transmission fluid cooler and installed a huge Hayden cooler in the floor of the engine bay on the drivers side. Now my temps run a lot cooler. Definitely worth it for me.

Glennman · June 06, 2020, 04:47:13 PM

Thank you Scott and Heather. I'll do some research into the Hayden cooler. Much appreciated.

Glennman · June 06, 2020, 05:03:00 PM

Ok Scott and Heather, I googled the Heyden coolers. What size did you install, and did you install a fan behind it? or, is that necessary?

buswarrior · June 07, 2020, 07:06:25 AM

Where's Tom C?

Maybe 20k btu heat rejection for the Allison? Don't quote me, been a long time...

Look for the ones with the biggest hose attachments, you want to be running that same big hose to it.

Measure the side door, the one that most folks are running will fit on the door.

Happy coaching!
Buswarrior

chessie4905 · June 07, 2020, 05:19:20 PM

1292 or 2305 Hayden. Both have 1" fittings.Even listed on Amazon and other sources.

Glennman · June 07, 2020, 10:42:56 PM

Do the Heyden coolers need fans installed over them?

chessie4905 · June 08, 2020, 04:37:42 AM

They need airflow through them to be effective. Whether the fan or fans need to run constantly or thermostatically controlled would be a choice. May want an override switch to bypass thermostat in some situations. Scott said his run constantly. In that case, may want to carry a spare fan in case of failure.

Scott & Heather · June 12, 2020, 02:06:28 AM

We went with the HDA-1297 cooler if I remember correctly. It's a heavy duty one pass cooler. It's huge so be sure you have the room to put it somewhere before you buy it. Summit Racing sells them. I do have a twin fan setup and it runs all the time. But your best bet would be to put the fans on a thermostatic Control.